Luminaire assembly for a divided highway



Jan. 9, 1968 D. w. HARLING ETAL 3,363,

LUMINAIRE ASSEMBLY FOR A DIVIDED HIGHWAY Filed Oct. 19, 1965 2Sheets-Sheet 1 1968 D. w. HARLING ETAL 3,

LUMINAIRE ASSEMBLY FOR A DIVIDED HIGHWAY Filed Oct. 19, 1965 2Sheets-Sheet 2 INVENTORS. DONALD ZZf. H/QRL //V6 1 I Y PH/L /P E. CL/QRKUnited States Patent Ofi ice 3,363,092 Patented Jan. 9, 1968 3,363,092LUIVIINAIRE ASSEMBLY FOR A DIVIDED HIGHWAY Donald W. Harling, Milwaukee,and Philip B. Clark, Hales Corners, Wis., assignors to McGraw-EdisonCompany, Milwaukee, Wis., a corporation of Delaware Filed Oct. 19, 1965,Ser. No. 497,632 11 Claims. (Cl. 240-25) ABSTRACT OF THE DISCLOSURE Aluminaire for being mounted atop a relatively short pole in the mediumstrip of a divided highway and including a generally tubular refractorand a hood for enclosing an elongate high intensity light sourcedisposed generally horizontally and in an oblique angular relation to aplane parallel to the roadway edge, and a semicylindrical reflectordisposed adjacent one side of the light source for reflecting light raysgenerally normally to the axis of the light source and in the directionof traffic flow.

Background of the invention This invention relates to luminaires and,more particularly, to a street lighting luminaire constructed andarranged to be mounted a relatively short distance above the roadway tobe illuminated.

This invention is primarily but not exclusively concerned with theillumination of divided roadways having a landscape median strip. Insuch applications, the luminaire must illuminate a relatively wideroadway on one side of the median strip without producing eye levelglare on either side. In addition, mounting poles of normal height areundesirable because they detract from the landscaping of the medianstrip.

It is an object of the invention to provide a luminaire suitable forbeing mounted atop a relatively short pole.

Another object of the invention is to provide a luminaire having aprecisely controlled light pattern for illuminating one half of adivided roadway from a relatively short pole without producing glare inthe eyes of motorists in either roadway.

Brief description of the drawings FIG. 1 shows the luminaire and supportpole according to the instant invention;

FIG. 2 is a side elevational view, partly in section, of the luminaireillustrated in FIG. 1;

FIG. 3 is a top view of the luminaire shown in FIG. 1, with the hood andsupport members broken away; and

FIGS. 4 and Saa-Sao are horizontal and vertical candlepower curves forthe luminaire illustrated in FIGS. 1 and 2.

Summary of the invention In general terms, the invention comprises thecombination of a relatively short pole and a luminaire including a baseportion, a refractor mounted on the base portion, a hood mounted abovethe upper end of the refractor, a high intensity lamp supported withinthe refractor, and a reflector disposed within the retract-or and on oneside of the lamp.

Description of the preferred embodiment Referring now to the drawings ingreater detail, FIG. 1 shows a luminaire which is mounted atop arelatively short pole 11, that is, in the order of three feet in heightor less. This is in contrast to the normal luminaire support poles whichgenerally range from ten to twenty-five feet in height. The pole 11 ismounted at its lower end on a mounting base 12 by means of a breakawaycoupling and electrical disconnect 13 so that the pole 11 will notpresent a traflic hazard.

Referring now to FIGS. 2 and 3, the luminaire 10 is shown to include abase 14, an optical assembly 15 and a lamp support assembly 16. The baseassembly 14 secures the luminaire 10 to the pole 11 and supports theoptical assembly 15 and the lamp support assembly 16 in their properrelative positions.

The base assembly 14 includes a slipfitter 18 integral with its lowerend and which has a cylindrical internal recess 19 for telescopinglyengaging the upper end of the pole 11. The upper end of the surface 19terminates in a V-in-section groove 21 for engaging the upper end of thepole 11 to center the luminaire 10 relative thereto. A plurality of setscrews 22 are positioned in spaced relation adjacent the lower end ofthe slipfitter 18 and extend through threaded apertures formed thereinto positively clamp the luminaire 10 to the upper end of the pole 11.

The lamp support assembly 16 includes a generally L-shaped bracketmember 24 which is mounted atop a generally cylindrical portion 25integral with a base assembly 14 and which extends upward from the upperend of the wall portion 19. One leg 26 of the bracket member 24 issecured to the base portion 25 by screws 28 and the other leg 29 thereofextends upwardly from the portion 25 for supporting a horizontallyextending yoke member 31.

A pair of spring loaded compressible lamp holders 30 are suitably fixedin an opposed relation to the ends of each of the arms 34 of the yokemember 31 for supporting a high intensity lamp 35 with its longitudinalaxis extending substantially horizontally. While the lamp 35 may be ofany high intensity type, in the preferred embodiment it comprises aquartz iodine type lamp which consists of a small diameter, hollow,elongate quartz tube which encloses a tungsten filament and is filledwith an iodine gas.

A vertically extending semicylindrical reflector 37 is secured to theyoke 31 by screws 38 for reflecting the light rays emitted from one sideof the lamp 35. Further, the reflector 37 is oriented so that its axisof symmetry is perpendicular to and lies in the same plane as thelongitudinal axis of the lamp 35 so that it will reflect a substantialportion of the light emitted from one side of the lamp 35. In addition,as seen in FIG. 3, the lamp 35 has oriented so that its longitudinalaxis is disposed at an angle of substantially 45 to a line AA which isparallel to the side of the roadway being illuminated and divides theluminaire 10 into a street side comprising the lower portion of FIG. 3and a curb side which comprises the upper portion thereof. In addition,the lamp 35 and the reflector 37 face in the direction of vehiculartravel indicated by the arrow 39.

The optical assembly 15 includes a refractor 40 and a reflector or hood41. The refractor 40 is a generally tubular open-ended lighttransmitting member having a plurality of light redirecting prisms 43formed on its inner and outer surfaces and is provided to redirect thegenerally horizontally directed light rays from the lamp 35 into thepredetermined light pattern. The lower end of the refractor 40 issupported by an annular refractor support ring 44 integrally formed atthe upper end of the base 14 and which includes an annular generallyhorizontally disposed refractor receiving surface 46 which terminates inits inner periphery in an upwardly extending positioning rim 5%. Inaddition, an annular gasket 49, of any suitable compliant material, isdisposed between the surface 46 and the lower edge of the refractor 40.

The hood 41 is secured in an overlaying relation to the upper end of therefractor 4t) and serves to redirect upwardly directed light raysdownwardly and into the desired light pattern. The reflector issupported in an abutting relation against the upper edge of therefractor by a plurality of V-shaped wire members 47 which are disposedinteriorly of the refractor 46 and which are suitably secured at theirlower ends to the base 14. The Wire members 47 diverge outwardly andengage a reflector support member 48 at their upper ends.

As seen in 'FIG. 2, the reflector support member 48 has a central hub 53and a plurality of spaced arms 55 which are affixed at their outer endsto the upper ends of the wire members 47. The reflector 41 is mounted onthe reflector support member 48 bya screw cap 57 having internal threadswhich engage external threads formed on the outside surface of the hub53.

FIG. 4 illustrates the application of the luminaries 11) according tothe instant invention to a divided highway having a pair of roadways 60separated by a median strip 61. The luminaires 10 are disposed in astaggered spaced apart relation along the opposite sides of the medianstrip and each is oriented so that the center line of its associatedlamp 35 is disposed at substantially a 45 angle to the edge of theadjacent roadway and facing generally in the direction of traflic flowindicated by the arrows 39. This produces the horizontal light pattern62 illustrated in FIG. 4 and light intensities taken through verticalplanes aaa as shown by FIGS. Saa-Sao. It will be appreciated from thesecandlepower curves that the light on the oncoming traflic side of theluminaire is held to a very low candlepower value so that at a distancethe luminaire appears as a very dim light. Upon reaching the area ofhigh illumination, the motorist is past the point where he will belooking directly into the luminaire. It can also be seen that the lightintensity of the median strip side of the luminaire is also held to arelatively low value so as to illuminate this area while not producing ablinding effect on drivers traveling in the opposite direction.

In addition, because of the low mounting height of the luminaire andbecause the main light beam is shown in FIGS. Saa-Sao is substantiallyat an 85 angle to the nadir, the light rays do not enter the rear viewor side mirrors of the vehicle and reflect back into the eyes of thedriver. In addition, because the candlepower distribution curve is quitenarrow with the main beam concentrated at 85 from the nadir, there willbe no bright pool of light on the roadway near the luminaire.

With reference to FIG. 2, it can be seen that the semicylindricalreflector 37 performs the function of cutting off direct light rays for45 from a line parallel to the roadway and on the oncoming traffic sideof the luminaire. In addition, the reflector 37 performs the function ofincreasing the light intensity in the direction of traffic flow.

The hood 41 performs the function of providing low level light intensityaround the base of the luminaire and at the rear of the reflector 37. Asseen in FIG. 2, the central bowl-shaped portion 65 of the hood 41reflects the light rays W and X above the top of the reflector 37 andtoward the opposite side of the luminaire. In addition,

the outer dished portion 66 of the hood 41 reflects the light rays Y andZ at a relatively steep angle downwardly behind the reflector 37 and atthe same side of luminaire.

' p This provides illumination around the base of the luminaire andbehind the reflector 37.

While only a single embodiment of the luminaire has been shownanddescribed, it is not intended to be limited thereby but only by thescope of the appended claims.

We claim:

'1. The combination of a relatively short pole, a luminaire mounted atopsaid pole and including a base portion, a refractor mounted on said baseportion, a hood mounted above said refractor, a high intensity lampsupported within said refractor and having an elongate light source andincluding lamp support means mounted on said base for supporting saidlamp with the longitudinal axis of said source disposed substantiallyhorizontal, a reflector mounted within said refractor and disposedadjacent one side of said lamp, said luminaire being divided into a curbside and a street side 'by a vertical plane passing through itslongitudinal axis, the longitudinal axis of said light source beingdisposed at an oblique angle relative to said vertical plane,substantially all of the reflector lying on one side of the longitudinalaxis of said lamp for reflecting light rays from said lamp generallytoward the street side of said luminaire.

'2. The combination set forth in claim 1 wherein said hood reflects atleast a portion of the upwardly directed light rays from said lampdownwardly behind said reflector and around the base of said pole.

3. The combination set forth in claim 1 wherein said vrefractor isgenerally tubular and has one end engaging said base portion and theother end engaging said hood,

and wherein said reflector comprises a cylindrical section with its axisof symmetry disposed generally vertically.

4. The combination set forth in claim 1, wherein said lamp is of thequartz iodine type disposed with its longitudinal axis disposedgenerally horizontal.

5. The combination set forth in claim 1 wherein the right end of saidlight source as viewed from the street side of said luminaire is closerto the curb side thereof and wherein the left side thereof is closest tothe street side of said luminaire.

6. The combination set forth in claim 5 wherein said reflector facesgenerally toward the right side of said luminaire as viewed from thestreet side thereof.

7. The combination set forth in claim 6 wherein said reflector isgenerally semicylindrical.

8. The combination set forth in claim 7 wherein the longitudinal axis ofsaid lamp is disposed at an angle of substantially 45 relative to saidplane.

9. The combination set forth in claim 8 wherein said refractor isgenerally tubular and has one end engaging said base portion and theother end engaging said hood, and wherein said reflector comprises acylindrical section with its axis of symmetry disposed generallyvertically.

' 10. The combination set forth in claim 9 wherein said reflector issymmetrical relative to a horizontal line normal to and bisecting thelongitudinal ,aXis of said lamp. 11. The combination set forth in claim10, wherein said lamp is of the quartz iodine type.

References Cited UNITED STATES PATENTS 3,145,934 8/1964 Guggemos 240-253,226,536 12/1965 Alkin'et al. 2403 FOREIGN PATENTS 655,413 1/1963Canada.

1,131,806 6/ 1962 Germany.

NORTON ANSHER, Primary Examiner.

W. M. FRYE, Assistant Examiner.

